反应详情

To a solution of Example 2A (265 mg, 0.415 mmol) in anhydrous dichloromethane (4 mL) was added trifluoroacetic acid (Aldrich, 0.320 mL, 4.15 mmol). The solution was stirred at room temperature overnight, then saturated sodium bicarbonate solution was added to adjust the pH to 9. The mixture was extracted with dichloromethane (3×15 mL). The combined organic extracts were dried over sodium sulfate, filtered, and concentrated by rotary evaporator. Purification by flash chromatography (silica gel: 50-100% ethyl acetate in hexanes) afforded 202 mg (90%) of the title compound. 1H NMR (DMSO-d6) δ 0.94 (t, J=7.3 Hz, 3H), 1.08 (s, 3H), 1.10 (s, 3H), 1.30 (d, J=6.8 Hz, 3H), 1.34-1.46 (m, 3H), 1.77-1.87 (m, 3H), 4.19-4.32 (m, 2H), 4.53 (t, J=7.3 Hz, 2H), 5.08-5.18 (m, 1H), 7.39 (d, J=8.8 Hz, 1H), 7.84 (dd, J=8.6, 2.2 Hz, 1H), 8.03 (d, J=4.4 Hz, 1H), 8.23 (d, J=2.0 Hz, 1H), 8.50 (d, J=5.1 Hz, 1H), 9.03 (s, 1H). MS (ESI+) m/z 539 (M+H)+.

1. extractionThe mixture was extracted with dichloromethane (3×15 mL)
2. dry with materialThe combined organic extracts were dried over sodium sulfate
3. filtrationfiltered
4. concentrationconcentrated by rotary evaporator
5. customPurification by flash chromatography (silica gel: 50-100% ethyl acetate in hexanes)